Empirical
by jenni3penny
Summary: "He didn't do this to DiNozzo – not so questionably and intimately close. And with Abby it was sweet – it was always sweet. He was affectionate with Ducky, in a friendly masculine way. But this closeness, it seemed reserved for her." Kibbs.
1. Chapter 1

It had started as her own sort of... internal investigation.

It wasn't case related (with the exception of the fact that most evidence was accrued while on duty, while on a case).

Were she Abby, it'd be more of a sort of a... scientific experiment.

And, really, it was a combination of both she supposed.

Because Abby had been the one to actually notice it first (rather, to actually voice it).

" _It's good that you stand up to him. He likes that."_

" _What?"_

" _When he gets close to you. You don't back down."_

She'd unconsciously known that, really. She'd _physically_ known it - her skin had intrinsically realized the proximity of him was both a threat and a guarding and a snare of possession at once. Because he had no issue with leaning long up the back of her, or angling himself demanding and directly into her personal space. He'd never had any qualms about reaching for her wrist or using the flat of his palm to shy her back into some sort of safety.

He had no sense of personal space when it came to her, no respect for the damn oxygen she was breathing into her body. He'd pinned her to her own desk, knocked her unceremoniously to the ground, shoved her out of danger, pulled her into safety, slapped at her fingers, drawn her closer, pressed her away. He'd been gentle against her, softly reaching, but sometimes rough and tough and some days those hands... those damn beautiful hands...

Some days it infuriated her.

(He didn't do this to DiNozzo – not so questionably and intimately close. And with Abby it was sweet – it was always sweet. He was affectionate with Ducky, in a friendly masculine way. But this closeness, it seemed reserved for her.)

Other days it was... all the fresh soap and saw-dusted (all _male_ ) smell of him up in her nostrils and invading her lungs.

Sometimes it made her unconsciously lean just close enough back that they'd hold a tentative touching for moments, uncountable, unintentionally intentional.

Sometimes it was the only way she had of touching him, so she pressed back into his forward momentum, before he could withdraw from the realization of how close they were.

She knew that (sometimes) he let himself swallow the smell of her hair.

And at other times he just held still into how warm the press of his one part to her one part was.

So... she'd made a study of the uncharted moments, made a case study of his closeness.

She'd started testing his resolve in how close to her he could bring himself to really, _really_ , be.

* * *

So, sure, yeah, she'd grabbed onto his sleeve and tucked her fingers closed, letting herself hang on. So, yes, first test was innocuous, innocent, not anywhere near an intimation of possible intimacy. At the moment when she would have usually pulled away she stubbornly dug her fingers tighter into the thickly warm and lush fabric of her favorite coat of his, clinging into the chocolate brown of the fabric. Then she swung half away from him, reflexively avoiding seeing his first reaction as she continued to hold tight, slinging something back toward where Tony was still in the truck.

When she looked back he was just quirking an unreadable smile at her, possibly both humor and confusion haunting it over his lips before she took the chance of wiping her fingers down the back of his arm.

"Photos?" She was already stepping away from him, easing back from the test of the touch.

He nodded agreement, glance thinning as he continued to watch her step away.

First results were... sorta inconclusive.

Which meant she'd need to obtain more results.

For comparison purposes. That's what she told herself.

* * *

It had been enterprisingly gently fixing his collar that made him swallow like his throat was lined with sharded up glass, slowly and carefully and with a near groaning of (the sweet sort of) pain.

His eyes had cast over her briefly as she smoothed his lapel down. And she'd intentionally ignored the shockingly blue searching of his glance, acting as though editing his clothing was both acceptable and normal.

In fact, she'd refused to meet his reaction at all – which had led to his fist clenching fast and tight as she'd continued stepping on around him with a polite "Excuse me.".

* * *

She pressed her fingers along his stomach, half shifting past him but stalling along his desk as she reached for the remote to the plasma. She'd been nodding agreement into something Tony was saying, most of her attention on the image she was pulling up on the screen even as a slim percentage of her brain was focusing on the strong swallowing breath he took, his lungs expanding under the flat press of her hand as she left it where it was.

She ignored the fact that he was intently staring at her (pretended to ignore it, really).

She rubbed her thumb deep into his chest as she answered Tony, a supposedly bored tone in her voice.

Then he caught along her elbow and turned the both of them toward the screen.

And she smirked into how soothingly he rubbed up the back of her arm before both their hands dropped.

* * *

It was DiNozzo's squinting tip of the head that had made him realize maybe... maybe he wasn't imagining it. Maybe he wasn't going absolutely _flipping_ _stark fucking nuts_. Because when she'd intentionally stepped around the autopsy table, into his space, and (it seemed like purposefully) brushed herself grazing against his crotch... he'd thought, for a moment, that he was going round the bend.

She'd had plenty of space in the other direction.

Even if Tony _had_ been to her left.

(Which, he assumed was why Tony had noticed at all – more a self conscious questioning of whether she was avoiding _him_ , not wondering why she was rubbing all over the boss.)

"You going with her or not?" He waved his fingers toward the door and the younger man's attention snapped back into the moment.

DiNozzo's head went back and forth quickly, still shaking off confusion as he took the opposite route around the table. "Sure, Boss."

He pressed his palm flat to the table and turned bent into the fact that, sure, yeah, her ass slowly sliding against his cock was something that _was_ noticeable and _did_ cause a twitch of a reaction. And he hadn't been the only one to notice that she'd obviously made the movement for a purpose. He'd be damned if he knew what that purpose was though, besides possibly giving him the sharp beginning of a half a hard on.

Gutsy little minx...

This had to be... she had to be making a (really inappropriate) point of some sort.

He just wasn't sure, as he knuckled into the metal table and talked his lower brain down, exactly what point she was so hell-bent on making.


	2. Chapter 2

"You avoiding me?" Tony's voice was oddly shushed and concerned.

And it confused the hell out of her. "What?"

"You're avoiding being near me, Kate." It wasn't often that such a self conscious emotion battered on his lowered shoulders and she watched him shrug as his face neared pale. "I mean, I know I'm... I'll stop messing with your stuff if that's what's bothering you. I didn't mean to, I mean, I never meant it to go this far. That you have to..."

 _You idiot. I do know how to lock a drawer if it really bothered me all that much._

She couldn't help but laugh into his little boy stumbling.

"Why are you laughing?"

She chuckled again, shaking her head as she grabbed up her bag and waved between their desks. "I'm not avoiding you, Tony."

"You keep putting Gibbs between the two of us." His argument was lowered toward the floor as he waited her out, a hand up to imply that she should go first. "It was never my intent to - "

"I'm not avoiding you." She leaned up closer to him to make the point as her knuckles nudged into his chest playfully. "He has no concept of personal space."

"So?"

"So," Kate shot back a smile as he started following after her, the both of them headed through the darkened office and toward the elevator, "I'm giving him a good dose of his own medicine."

"He doesn't realize he's doing it, Katie-Cat." Tony was ruefully smiling, shaking his head through the bemusement as he sped his steps up and jammed at the button before she could reach it. "Not with you."

 _Not with me?_

"What do you mean by that?"

"Exactly what I just said." His bag got jerked higher on his shoulder as he nodded and swayed into his own argument. "He has no idea that he's making you uncomfortable. He can't help himself. Not with you."

 _Not with me._

 _He can't help himself... with me._

"It's not... I'm not uncomfortable." Her head unconsciously angled toward her shoulder and she felt herself sway a little into the movement, surprised by the fact that it had drawn a smile over her lips. "Not necessarily."

"You like it," DiNozzo surmised quietly as they waited out the elevator. "Then why are you - "

"Because he has no idea he's doing it." Her confession warmed through her lips, a shrugging on her that seemed slightly embarrassed, blushing her cheeks a shade darker.

 _And I want him to know._

Tony blinked into an understanding grin, his head and shoulders leaning back slightly as he studied her face. Then a mild concern colored over his eyes as his head tipped and he aimed toward her, "This could backfire on you, ya know?"

"I know," Kate admitted gently.

His grin came back, wider than before. "You can't help yourself either, can you?"

* * *

Abby seemed to have been making notations and observations herself. And it seemed as though she was perfectly willing to help the experiment along. Because even she'd supplied her own test of sorts.

She'd excitedly gone bumping him aside and back from her desk and intentionally into Kate's space with her head turned toward her computer, her smile swallowed down as far as possible as she made a show of typing. And Kate had taken advantage of his shifting, letting the tall and broad back of him slant into her front, her palms catching along his ribs and digging him still, as though (of course) she was just keeping him balanced.

Of course she was. _Of course._

With her hips and the entire front of her body while she stroked both palms down his ribs and smirked into how quickly he side-stepped from her space. A sheepish and nearly blushing ( _good God, did the man actually just blush?_ ) look shot back in her direction, half a smirk twitching his lips as he turned a look over her feet to be sure he hadn't trodden on them and just angled aside.

"Sorry, Kate."

 _Good God... did the man just actually apologize?_

* * *

He was stalled by the lift of Ducky's head, the way the older man silently implied paused questioning as the others headed for the elevator. Gibbs waved off the look Kate flashed back at him as she jammed the button, turning his shoulder to her watching as he stepped entirely back into the room and leaned opposite the medical examiner.

"Whatcha need, Duck?"

There was a bridge of a moment wherein Mallard seemed to consider a long list of things all at once, just before he exhaled and leaned forward, "Has something, have you and Caitlin - "

"Have we what?" He sharpened off between them, holding the other man's glance with a solidly flexed jaw and forcibly relaxed shoulders.

"Oh, thank heavens." Ducky's sigh was large and it echoed around in the spacious room, his entire body seeming to lower as tension loosened from it. "Finally."

"What?" Gibbs leaned farther forward, let his glaring thin a little more as his head tipped. "Finally what?"

"You two have - "

"No," he coughed it out on a strangled breath, "we haven't."

Mallard's head jerked back in obvious surprise, his eyes going dark behind his glasses. "Are you sure?"

 _Am I sure? Oh, yeah, I'm pretty damn sure._

"I'm positive, Duck," a grin nearly made it half into the response. "Why would you think - "

"The two of you can't keep to yourselves." There was a slight impatience to Mallard's tone, a way in his words that implied he was more frustrated with the situation than he'd otherwise let on. "Which is nothing unusual, mind you. However, it seems more... intense as of late."

 _Can't keep to ourselves? And that's nothing unusual?_

 _If I was keeping that woman to myself there'd be a whole lot more touching going on than there actually is..._

 _But..._ "You noticed it too?"

Ducky's head lifted quickly into the other man's softened question, shaking slowly and barely noticeably as he squinted between the two of them. His face seemed near distrustful, as though Gibbs was just messing with his mind. "You're sure nothing's happened?"

"Duck, I'd remember." Gibbs quieted his tone, laid it out with as much patience as possible. "Trust me."

 _That's so not something I would forget. Trust me._

A smile moved over the older man's lips, something distinctly proud and amused. "Then she's - "

"Yeah, she is," Gibbs agreed on a jerked nod and a thick swallow, letting his head dip forward conspiratorially. "She's playin' with me."

"Or she's simply tired of it being a one-sided arrangement and she's taking advantage of your continued proximity."

 _What? A... a one-sided what? Proximity to what?_

 _What the hell?_ "One-sided what?"

"Jethro," he shook his head slowly down into a sort of wry knowing, "you guard that woman."

"She's my agent. Yeah," he defended quickly, shoulders jamming straight up again as he pressed back from his side of the empty table.

Ducky gave him a look so thick with disbelief and self-satisfied knowing that he had to avoid the older man's eyes, turning his jaw aside.

"Then I'd ask you to treat Antony's personal space in the same manner," the doctor's voice was surprisingly soft in the accusation. "Just for one week."

Gibbs lifted a hand between them and waved away the argument, as though it was ridiculous. "I dunno what you're talking about."

"You really don't realize, do you?"

 _Realize what? Yeah, okay, I tend to... 'guard' her._

 _She's my agent. I take care of my own. And she's mine._

 _She's mine..._

"Realize what?" Even he could taste the stewing darkness in the words.

"She's not playing with you, Jethro." The older man waved his fingers idly across the table. "She's forcing your hand."

Gibbs watched the medical examiner turn away from him, his hand waving up as though no response was needed, warranted or wanted. "And good for her."

* * *

He'd, admittedly, lost a little patience with it at one point.

Because she'd leaned too far back in her game and made one misstep that he caught ahead of time, one he'd seen coming. So he curved her closer by palming his hand onto her pelvis when he was sure nobody else was aware of the movement.

And he'd purposefully laid a hot breathed groan into her hair as he'd driven his hips forward and hers back, rubbing against her pelvic bone with slow fingers as he'd grazed his mouth against her hair.

The whimper she'd just barely made audible was enough to give him a grin.

And he'd wiped his fingers flat down her thigh before stepping away and leaving her staring widely after him.

Some battles just _had_ to be won.

Some lessons _had_ to be taught.

* * *

At one point, it wasn't a test of anything at all.

Well, at least not anything near the playful and (supposedly) secret little experiment.

If it had been a test of anything, it'd been of his reflexes and how quickly he could duck her to the ground as a car exploded half a block away.

There'd been no silly motive or underlying reason for grasping his fingers in hers as he'd cradled around her, his arms wrapped tightly around her shoulders as their heads bent in unison from the sound and debris. The full weight of him crowded her down and bent her nearly halved, his chest dwarfing her as he pinned her still. She'd merely turned her head into his neck and curbed out a whimper, squeezing her eyes shut as a sound that seemed half relief and half comfort expanded through his lungs.

His hand shakily stroking along her hair, nearly threading into it as he audibly swallowed by her ear - it was the sweetest touch she could have named since she'd started paying so much attention to the nearness of him.

They hovered a moment in that closeness, her breathing hot against his neck as he put another stroke of comfort along her hair.

"You okay?" She'd swear (give her the Bible to put her palm to) he'd kissed it against the side of her head.

She nodded as his fingers traveled to her shoulder and squeezed lightly. "I'm fine."

"Kate - "

"Really." She couldn't help but laugh relief, lifting her head as he slowly stood away from her and offered a hand. "I'm fine."

The quickness of his fingers grasping hers and tugging her up had her head rising into the unbreakably focused way he was studying her. "Kate."

She tried guarding her smile and failed miserably. "I'm fine, Gibbs."

* * *

She may have miscalculated brushing her knuckles back and forth against his in the weighty silence of the elevator, regardless of how loosely he'd stretched his fingers out to meet the purposefully slow back and forth shifting.

At least she thought maybe she had, until two of his fingers had snagged around one of hers, flexed curling around it for the length of two floors and holding. And then suddenly gone when they reached their floor.

Now, _that_ was evidence of something.

Something... that just _couldn't_ be misconstrued.

"Caitlin." The way his voice snagged on her name was nearly as abrupt as the way he jerked her back into the elevator and kept his fist closed into the back of her shirt until the doors slid closed again. "I'm not stupid."

"No." Her response was breathless because (as was usual) when he got his hushing voice so close to her shoulder, her lungs seemed to stop working. "You're not."

"If you wanna touch me then do it." But there was a strangled sort of impatience to his tone this time, a frustration that could have easily veered toward angry. "Stop messin' around."

She should stop messing around? Stop teasing and breathing and swaying too close to him?

Stop touching and looking and watching and... damn him.

Damn him to hell for that.

"I could say the same to you." She spat to the side, feeling scrubbed raw by his accusation regardless of the fact his thumb was rubbing just to the left of the line of her spine.

Screw him for being gentler in his touch than expected while his voice was so ruggedly harsh.

So damn... sexual, actually. Intimate... maybe.

She needed that tone again, needed another round of it.

Because she wasn't sure if he was being 'asshole' or 'aching'.

She needed more evidence.

"Me?" It seemed as though legitimate surprise was wondering in his voice. "You're the one - "

"You're the one who can't keep his eyes to himself." Kate lifted her jaw stubbornly into his rebuttal, actually surprised by the fact that there was a calm innocence to the angle of his head over her shoulder. "Can't stay in his own goddamn space."

His brows went up, head shaking marginally back and forth as he dug tighter into her shirt and leaned his body angling into her shoulder, driving farther up the side of her so that not touching was an impossibility. "And you think groping me is a proportional response?"

He was aching all over her. Visibly, audibly, and unapologetically.

The very realization made her swallow hard, nearly gulping down oxygen that smelled more like the nearness of him than the staleness of the elevator.

"I haven't even come _near_ groping you, Agent Gibbs." She admitted softly, letting her head tip nearer to the lean of his jaw, dropping her eyes as mild embarrassment touched her cheeks pink.

"If you wanna touch me, Kate," his voice guttered out a little as his head leaned into the side of hers, connecting them from top to the twist of his knuckles digging into her lower spine and farther to his pelvis driving along her side. "then touch me."

She closed her eyes and just enjoyed the empirical results of an impractical experiment. "I could say the same to you."

"Sure," he kissed the quiet agreement along her ear, shivering her under the hushed lull of his softened voice, "but I said it first."


End file.
